Osananajimi no Mama ja Dekinai Koto

I'm dating my childhood friend "Yuzu", and the two of us are playing games at my house like usual. But today, it looks like I have a mission: it's our 100th day since we started going out! So I pretended that I was having a stomachache, leaving Yuzu's side for a moment and dashed out of my room so I could prepare a surprise for her, when...

Huh?! Yuzu, who was left alone by herself, went hunting for hidden things in my room as payback, finding my erotic books; even worse, she also found the DVDs that came with them...

"Yu- Yuzu!! That... Where did you... ", I stammered as my mind went blank.
"Let's break up...", Yuzu cried while sulking.

"You don't even try to hold hands with me."
"I'll get hurt if you keep treating me like your childhood friend."
With our hearts pounding, we spill our true feelings and real intentions to each other, and then gathered the courage to do the things that we can't do if we were just childhood friends.

This is a story about an innocent and clumsy couple in the springtime of their lives.

(Source: BookLive, translated)

Note: Published in 2 versions, a fully censored version and an R-18 version with mosaics. Censorship differences aside, the story is the same.